While your 3D model may look like a perfect door handle or light-saber in your 3D modeling software, the 3D printed model may well turn out to be a mess. Misprints and failed prints are an all too common problem.

But fear not! There are a range of STL repair tools — on both desktop and the web — that will help you identify problems and even fix your models for successful printing.

Below we’ve listed the big repair tools — web-based tools first — along with what they offer, file types they play nice with and platforms they are available on.

18 Best STL Repair Software Tools of 2018

What is it? Arguably the top German 3D printing service. Trinckle places a focus on 3D printing for business, with a robust web-based platform allowing rapid iteration and customization of 3D models. But their powerful repair tool is open to all online, allowing for quick model analysis and simple one-click repair.

It’s come to our attention that if your model isn’t critically broken (and Trinkle deems a few design suggestions sufficient to get it printed), you won’t see the option to re-download your fixed model. So, if you don’t see the option to download, your best bet is to try one of the others listed here.

Though for those with an STL Trinckle can repair, a simple one-button fix option will appear upon upload. You won’t get a detailed overview of what’s changed after Trinckle fixes it — just a basic list of how many errors are fixed. But the upshot is you can download the repaired file in an instant.

What is it? Another great free STL repair tool is built into an online 3D printing service: Sculpteo. After uploading your 3D file you are given the chance to analyze and repair by Sculpteo’s advanced repair algorithms.

You repair your STL file by choosing from a list of options that are tailored to common use cases. For instance, CAD models, architecture models, or small miniatures. In case you are not satisfied with the result, you may try the other options or upload the file anew.

While this very convenient tool is free, you can’t download the repaired STL file for 3D printing it at home. It is solely designed for the purpose of buying a 3D print from Sculpteo.

What is it? Microsoft’s toe in the water when it comes to STL repair. Using its own skin over the Netfabb Cloud Service, the tool enables users to analyse their STL files according to parameters such as dimensions, volume, surface area and more before repairing the mesh. If you don’t have access to the desktop version of Netfabb but want to make use of its STL repairing algorithms, you should give this service a go.

The entire process is conducted off-screen and you get no print preview, but for a free and simple process, what more could you ask for. The only drawback we see currently, besides having to log-in with a Windows ID, is that you can only download your repaired file in the progressive, but still fringe 3mf file format.

What is it? 3DprinterOS is a 3D printer managing software that wears a lot of hats. To start off with, it is a 3D modeling tool. But among its other features are multiple slicers and social networking capabilities. In addition, 3DPrinterOS is happy to 3D print your STL files using its industrial printer factory. A variety of web-based apps plug into this virtual OS, most important to this list is Magic Fix. In addition to STL repair, it also scales and rotates your file for dozens of popular 3D printers.

What is it? This web service checks your STL files for any mistakes that might corrupt the print and fixes them. Unlike most of the free online services though, MakePrintable gives an impressive level of control. You can choose a quality level (prototype, standard and high), hollow and repair STL files and optimize the polygon count. It even allows you to merge multiple meshes into one.

In the free version, users can repair non-manifolds, flipped-faces, boundary edges and intersecting objects on 3 models a month. For advanced options like instant repairs, texture support, hollowing support and adjustable wall thickness, the paid commercial option ticks the box. It also boasts plug-ins that connect it seamlessly with the 3D modeling software Blender and Sketchup.

What is it? This online STL repair service promises that you won’t have to “worry about printability issues anymore”. Integrated into the Materialise ecosystem, you can find a convenient tool to repair STL files automatically. Other features include scaling, setting the wall thickness, adjusting the polygon count and hollowing the meshes before printing them. If you register for Materialise Cloud, you will receive ten STL repairs free of charge. A robust service that emphasizes convenience.

What is it? MeshLab was designed for processing and editing unstructured 3D meshes — issues that raw 3D scans can often produce. In general, its tools allow to edit, inspect and repair STL files. However, MeshLab is specifically capable of automatically filling holes in meshes. This level of control requires a good deal of technical knowledge in order to apply the tools appropriately. Unfortunately, there is little in the way of official documentation available for MeshLab, but we’ve covered this gap with our own mini STL repair tutorial — check it out.

At first glance, 3D Builder is merely a free 3D modeling software that is available for desktop PCs and other Microsoft platforms (Windows Mobile, Xbox One, and Windows Hololense). However, this user-friendly piece of software also includes some basic STL repair functionalities that will make your design 3D printable.

Using the touchscreen interface with gestures, editing and tweaking 3D files is quite an immersive experience. The integration into the Windows phone has another perk: This free STL repair tool also enables the user to scan objects and convert them into 3D files using the device’s camera. Simply take a series of photos of the object from several angles, and images are stitched together to recreate the object as a 3D model.

Best STL Repair Tool for: Beginners who want to get their files ready for 3D printing.

What is it? The self-described “Swiss Army Knife” for 3D meshes is more than a simple STL repair tool. Indeed Meshmixer is a fully fledged modeling solution that is also capable of hollowing, scaling and mesh simplification. Meshmixer is no beginner’s tool, but if you are looking for a 3d printing tool that seamlessly blends into the Autodesk product family, look no further.

A recent update to this STL repair program has, alongside a raft of bug fixes, taken its capabilities further. Including support for the versatile 3mf file format.

What is it? If you’re undecided about which which modeling software to pick, Blender is worth closer inspection. Over the last two decades, Blender has become the standard open-source tool for 3D modeling and animation. Moreover, the program provides a solution for STL repair, correcting meshes intended for 3D printing. Blender is not suited for beginners, but if you are searching for an open-source jack of all trades at the friendly price of free — this is it.

What is it? An open-source 3D modeling program that was designed with the needs of mechanical engineering and product design in mind. Among the many features of this program is the capability to repair STL files. If you are looking for a tool that gives you a high degree of control over your work – FreeCAD may be the way to go. It can do a lot more besides repair STL files – check All3DP’s FreeCAD beginner tutorial right here.

What is it? Emendo is aimed at providing an automated platform to prepare and to repair STL files before printing. Therefore it is suited to beginners who are willing to pay for the convenience it offers. However, be aware that similar functionality is freely provided by other solutions like Netfabb Basic.

What is it? A industry-level CAD agnostic tool for manipulating geometries at any point in the CAD workflow. Designed by engineering simulation specialists, SpaceClaim can repair STL files infested with “dirty” geometry, “shrink-wrap” faceted 3D models, alongside other familiar file prep processes such as shell and infill optimization.

What is it? MeshFix is an open-source STL repair tool that fixes various defects in meshes, such as holes, non-manifold elements and self-intersections. Unfortunately, MeshFix is only available for Windows. It is a great tool if you need a simple STL repair, but for more sophisticated options look elsewhere.

What is it? Supporting a plethora of file formats for import, this open-source 3D model and viewer boasts the nifty feature of a tabbed display that allows for viewing up four viewpoints simultaneously. In it, you can repair STL errors such as improper vectors and degenerate geometry removal. The project’s site also claims an update is coming soon (though no determinable date as yet — we’ll update in due course), which will add more robust mesh repair tools for fully prepping models for print. One to watch.

What is it? Netfabb is undoubtedly one if the best-known and most comprehensive solutions to repair STL files. Users of this STL repair tool can choose between a range of extremely powerful automatic, semi-automatic and manual repairing options – which allows for applying the best solution for each project.

However, Netfabb is not only one of the best STL repair tools on the market. It covers the entire setup process before 3D printing. To give a small taste of Netfabb’s many other capabilities, it can automatically pack marge numbers of parts into a build-volume. Allowing you to save money in terms of turn-around time and materials used.

Consult this table to find out which version of this STL repair tool suits your needs best.

Best STL Repair Tool for: Additive Manufacturing Professionals in need of a robust and versatile tool.

What is it? Another professional STL repair software with a significant price tag. LimitState:FIX’s mission statement is “Fixes the 3D models other tools can’t!”. Besides the auto-fix capability, the program enables the user to merge STL files, remove noise shells and simplify or repair meshes. Other STL repair options include closing solids, correcting non-manifold errors and fixing the orientation of polygons. LimitState uses robust Polygonica technology — a standard for professional 3D modeling industry for more than 20 years.

Cur3d is a comprehensive STL repair software that brings unique productivity features to the table. First, the program corrects the common hiccups in 3D files like gaps, wrong normals, and overlapping areas automatically.

Second, the true standout feature of Cur3d is its unique take on productivity. Scaling down a 3D file can result in features that are too minute to be 3D printed. Adjusting STL files for smaller scales manually is a time-consuming process. This is where Cur3d can help you. The program takes into account the desired scale and the resolution of your 3D printer and adjusts the STL file’s features accordingly.

The program can run in batch mode overnight. What is more, this STL repair tool includes a time-saving extension that allows you to view STL files directly within the Windows Explorer. Cur3D is an excellent STL repair tool that we would love to see for Linux and Mac.

Best STL Repair Tool for: Professionals who have to process a great number of STL files.

STL Repair Tips: Checklist for 3D Designers

An STL file isn’t automatically 3D printable. Small mistakes can trip up the print process, but they are easily remedied. Here are the most common design mistakes – and what you can do to repair your STL file, so your 3D model prints correctly.

STL Repair Tip #1: Repair Gaps in Meshes

One of the most common errors encountered when 3D printing are STL files that have holes in their meshes – they are not “watertight”. A 3D printer faced with such a file can’t tell an outer surface from an inner surface. Most of the STL repair tools we list can handle these 3D mesh problems easily.

STL Repair Tip #2: Check for Non-Manifold Geometry

Simply put, non-manifold geometries are identical edges directly on top of each other. Typically this conundrum results from extruding but not moving faces and edges. Non-manifold geometry startles 3D printers as much as anyone else who tries to wrap his head around the idea for the first time. Think about the graphic works of M.C. Escher and you’ll get the idea.

STL Repair Tip #3: Get rid of Floating Surfaces

3D scanning can produce unwanted fragments which result from structures or textures that are unsuitable to the process – e.g. hair, very dark or very bright surfaces. Scans can be reworked before printing by hand (e.g. MeshLab), but automatic solutions to repair STL files are also available in most STL repair software tools.

STL Repair Tip #4: Lose the Thin Walls

It is paramount to set a wall thickness that can support the overall structure. Depending on what use you will put your 3D model to, you must choose a thickness that will yield a robust model at an economic consumption of filament or other material.

STL Repair Tip #5: Minimize the file size

Many cloud-based STL printing services impose upload limits on the files you can upload, often ranging from 64 to 100 MB. This problem can be remedied by automatic down scaling (e.g. MakePrintable or Materialise Cloud) in your 3D design software.

Have we missed your favorite STL repair software? Let us know in the comments, and we’ll add them in a future update.